Germ cell tumor
As a germ cell tumor , also germinale (from the Latin. Germen , germ ') called tumors, different from the be germ cells outgoing tumors called. In the case of this type of tumor, it is decisive for the dignity whether it occurs in men or women. Germ cell tumors in women are usually benign ; in men, both benign and, more often, malignant forms occur. The germ- cord or stromal cell tumors , also called non-germinal tumors, and mixed tumors are to be distinguished from germ cell tumors.
pathology
Since the prognosis for germ cell tumors differs according to gender, the pathology of germ cell tumors is treated separately in the following according to gender.
Germ cell tumor pathology in women
Teratoma
95 percent of these germ cell tumors in women are benign, differentiated teratomas . Overall, these tumors make up 20 percent of all ovarian tumors. Usually only one ovary is affected by these tumors, in 20 percent of cases both ovaries can be affected. These tumors usually occur between the second and sixth decades of life.
Since teratomas often consist of cells from all three germ layers , the tumor cysts may contain sebum, serous fluids, hair, teeth, adipose tissue and muscles, depending on the degree of differentiation of the cells . Bone , cartilage , nerve or mucous membrane tissue are less common .
In addition, monodermal teratomas that consist of only one type of tissue can also occur:
- Epidermoid cyst , pure epidermal lining without skin appendages such as hair or glands
- Goiter ovarii , consisting exclusively or predominantly of thyroid tissue ; The ovarian goiter is the most common form of monodermal teratoma. It is rarely associated with an overactive thyroid or ascites . Only around five to ten percent correspond histologically to papillary thyroid carcinoma , although distant metastases are even less common.
- Carcinoid originating from gastrointestinal or respiratory tissue
The prognosis for female teratomas is good. The most common problems occur when the tumors are twisted. The malignant degeneration of the teratoma, which almost always occurs during menopause, is very rare .
The malignant teratoma occurs almost only in girls and young women. These tumors are usually very large and are characterized by rapid growth and early metastasis . You respond very poorly to radiation and chemotherapy . Elevated alpha-fetoprotein levels are often found in the laboratory .
Yolk sac tumor
This tumor is characterized by the fact that the tumor tissue of early embryogenesis resembles the yolk sac in particular . Under the microscope, the tumor cells are mostly undifferentiated and show a wide range of variations. There can be spherical arrangements, which are then referred to as Schiller-Duval corpuscles . These are small vessels with a hyaline wall structure that are surrounded by tumor cells in a ring. This tumor often affects patients who are younger than 20 years. The prognosis is unfavorable; the 5-year survival rate for this tumor is just over 50 percent despite polychemotherapy. With the tumor marker AFP the success of the therapy can be checked and the follow-up can be controlled.
Dysgerminoma
The dysgerminoma is derived from the pluripotent undifferentiated germ cells. It usually occurs between the second to third decade, and the average age of onset is 20 years.
The structure of the tumor is very variable and microscopically corresponds roughly to that of the seminoma in men. It is the most common genital malignancy in children, adolescents and pregnant women and is almost always a solid, multinodal tumor.
This tumor metastasizes lymphogenously and is sensitive to radiation . The good prognosis of this tumor (5-year survival rate of 70–75%) is therefore determined by the possible simultaneous occurrence of other germ cell tumors. With the tumor markers PLAP, LDH and CA-125 the success of the therapy can be checked and the follow-up controlled.
Chorionic carcinoma
This tumor is rare in women and microscopically corresponds to chorionic carcinoma of the placenta . However, the cure rate of ovarian chorionic cancer is extremely poor.
Germ cell tumor pathology in men
Pathogenesis
By DNA -zytometrischen investigations is now thought that all germ cell tumors of the man with a few exceptions of a seminoma out. The degeneration takes place in the following steps: first there is an intracellular increase in DNA in the corresponding gametes , which are then tetraploid . The further tumor progression is accompanied by a loss of DNA, the resulting seminoma cells are then aneuploid . In the further steps there is progressive loss of DNA and more aggressive types of tumors arise, such as embryonic carcinoma, which also manifest at a younger age. Due to the different treatment strategies, testicular tumors are divided into seminomas and non-seminomas.
Seminoma
The seminoma is the most common testicular tumor.
Embryonic carcinoma
This is a highly malignant tumor made up of cells with an epithelial character. This tumor most often occurs between the ages of 20 and 30. Macroscopically, the cut surface shows necrosis , bleeding and cysts. The microscope shows a mixed picture of solid areas and cavities; giant cells can appear.
Yolk sac tumor
This tumor, also called infantile embryonic carcinoma or orchioblastoma , is the most common testicular tumor in children under three years of age, while its occurrence in adults is very rare.
Chorionic carcinoma
The cells of this tumor mimic cells of the placenta . It usually occurs between the ages of 10 and 20. Occasionally, this tumor can also occur outside of the testicle, for example in the urinary bladder or the epiphysis . Chorionic carcinoma can be diagnosed by a large increase in the hCG level. Gynecomastia occurs in ten percent of cases, and the metastases of this tumor are mainly spread through the bloodstream, which happens early.
Teratoma
Depending on the differentiation of the tissue, a distinction is made between mature and immature teratomas. Mature teratomas are usually benign in children , while mature teratomas can metastasize in adults .
treatment
Seminoma
Nonseminom
Treatment depends on the stage of the tumor and whether the tumor has already metastasized. In the early stages there are several options that lead to a cure in around 99 percent of cases. The lack of vessel invasion by the tumor is beneficial.
- Primary surgical procedure by removing the retroperitoneal lymph nodes; Advantage: Surgical securing of the tumor stage, only around two percent recurrences in the retroperitoneum . Most patients do not need chemotherapy and follow-up care is easier. The disadvantage is unnecessary surgery, loss of ejaculation can occur, among other complications. Lung metastases are not reduced.
- Risk- adapted approach with close monitoring in the case of low risk and chemotherapy if there is evidence of vascular invasion in the primary tumor. The disadvantage of the wait-and-see attitude is that more chemotherapy is required than with primary surgery. There is a temporary reduction in fertility for about three years.
- Primary chemotherapy and surgery if lymph nodes are still enlarged after chemotherapy.
In more advanced stages, the therapy depends on the amount of tumor markers in the blood, the size of the tumor and the local involvement. It usually begins with chemotherapy, and in the case of very advanced tumors, also with high-dose chemotherapy. It should be noted that, outside of clinical trials, primary chemotherapy should include cisplatin in all non-seminomials and in the absence of contraindications .
literature
- S1 guideline for extracranial germ cell tumors of the Society for Pediatric Oncology and Hematology (GPOH). In: AWMF online (as of 2012)
- S1 guideline for germ cell tumors of the central nervous system of the Society for Pediatric Oncology and Hematology (GPOH). In: AWMF online (as of 2012)
